MUMBAI: The super rich will continue to get richer in the coming decade. The number of high net worth individuals in India with net assets of Rs 150 crore to Rs 160 crore is expected to more than double over the next 10 years, rising by 137% in Mumbai and around 120% in Delhi, says Knight Frank Wealth Report 2013.

The global property consultancy firm ranks India at 5th spot with 122 billionaires as of 2012 end in the top 10 countries for billionaires that are expected to increase to 225 billionaires with an 84% growth by 2022.

The report ranks Mumbai at the 7th spot with a total of 2,105 high net worth individuals in the top 30 global cities; while Delhi is at 11th spot with total 1,905 such super-rich individuals. By 2022, number of high net worth individuals in Mumbai is expected to increase to 4,988 with 137% rise; while Delhi is likely to see it growing 120% by then to 4,278.

"The rise of the Asian global cities is in parallel to what many are now calling "The Asian Century". With the historic shift in economic power towards Asia, its cities are undoubtedly going to become more influential in the coming years," said Nicholas Holt, Director Research, Asia Pacific, Knight Frank.

Across Asia, the number of HNWIs is set to rise by 88% over the next decade, the joint highest rate of growth in any world region. While New York and London top the list in the cities that matter to HNWI's, Mumbai stands only on the 38th spot of the top 40 cities.

"It is interesting to note that both Mumbai and Delhi are expected to grow at a high rate which is comparable only with fastest growing cities like Shanghai, Beijing, Rio De Janeiro and Sao Paulo," Samantak Das, Director Research & Advisory Services, Knight Frank India.

As per Knight Frank's luxury investment index, the super-wealthy are also set to step up their interest in "investments of passion" such as art, fine wine, classic cars, coins and watches this year, especially those in China. Knight Frank's luxury investment index shows that classic cars have seen the largest appreciation in value over the last decade, with an average uplift in price of 395%.